• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1063-1069
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• 2011

This paper presents aerodynamic power outputs of wind turbine of 6 MW wind farm composed of 3 sets of 2 MW wind turbine according to the separation distance by using CFD. Layout design including offshore wind farm and onshore wind farm is key factor for the initial investment cost, annual energy production and maintenance cost. For each wind turbine rotor, not actuator disc model with momentum source but full 3-dimensional model is used for CFD and it has a great technical meaning. The results of this study can be applied to the offshore wind farm layout design effectively.

• Journal of Energy Engineering
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• v.20 no.2
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• pp.143-153
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• 2011

Offshore wind power(OWP) is one of the most promising renewable energy and gives higher output than onland one due to stronger and consistent wind in offshore. it offsets shortcoming of noise, spatial limit and less affects scenery, and can be built in larger size. Korea has plenty of offshore wind resources as it is surrounded by the sea in three directions. This review describes recent progress in offshore wind turbine and substructure technology. Market trend in local and overseas, Number of papers published and patents registered are analysed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.2
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• pp.163-170
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• 2011

An optimal layout condition of the offshore wind turbines is studied by using the response surface analysis which is a kind of the design of experiments. Based on the assumption that total 36 turbines would be installed in the offshore wind farm, the number and distance of the rows and columns are used as the design variables and the efficiency decrease of power generation due to the wake decay by the interactions of turbines and the installation cost of the internal electric grid are considered as the objective functions of the response surface analysis for the layout design of turbines. Useful design information can be derived by analyzing the relationship between the design variables and target functions. It is found that the row number and the distance between rows should be minimized, and the optimal distance between columns should be estimated and adopted to the layout design within the specified design range in order to ensure the economics for the offshore wind farm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.306-315
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• 2010

As developing the large-scale offshore wind farm is expected, the preliminary environmental impact assessment is very essential. In this study, the wave hindcast model is verified based on observed data at the coast around Wido which is among the candidate sites for developing the offshore wind farm. In addition, the effect of the wind turbine foundations on wave height is analyzed when total 35 wind turbines including monopile foundations of 5 m in diameter are installed. Calculation result of significant wave height is in good accord with observed data since the RMS error is 0.35 m. Moreover, it is found that the presence of the wind turbine foundations hardly affects wave height as wave damping ratio is less than 1%.

• 기계와재료
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• v.21 no.2
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• pp.50-73
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• 2009

본 고는 중대형 풍력터빈의 핵심부품인 로터 블레이드, 대형베어링, 증속기, 발전기, 전략변환장치, 타워 등에 사용되는 주요재료에 대한 설명과 제조방법 및 평가 방법 등에 대해 다루어 졌다. 일반적으로 풍력터빈을 구성하는 소재는 금속소재와 비금속재료로 구분되며, 비금속재료는 대부분 복합재료로써 풍력 블레이드에 적용되고 있다. 현재 육상용 풍력터빈의 한계를 극복하기 위한 대안으로, 해상용 풍력터빈에 대한 관심이 집중되고 있으며, 이러한 극지 해상의 대형 시스템에 활용되고 있는 금속소재의 경우, 고강도, 저온인성, 내피로, 내식성 등이 우수한 강재를 요구하기에 이르렀다. 이에 따라, 여러 소재 측면의 요구를 충족하기 위한 소재설계의 비중이 점차 고조되고 있으며, 이러한 시점에 본 고를 통해 풍력터빈에 활용되고 있는 소재의 전반적인 내용과 관련 소재부품의 제조 및 평가 방법등의 이해를 돕고자 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.404-408
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• 2007

현재 국내에서 운용중인 풍력발전시스템은 국내 풍력자원에 대한 정확한 정보의 부재와 국내 풍황에 맞지 않는 국외 모델을 그대로 운용하는 등의 몇 가지 문제를 드러내었다. 본 연구의 목적은 국내 연안의 해상에서 한국형 해상풍력터빈을 설치하기 위한 잠재적 최적위치와 풍황자료 산출 최적화 알고리즘을 구현하는 것이다. 최적화 알고리즘은 얕은 수심 분포와 연안에서의 거리를 제약조건으로 하고 최대 에너지밀도를 가진 지점을 구하는 것으로 정식화하였다. 풍황자료 산출을 위해서 국내 연안의 해상 풍황자료를 포함하는 기상풍황자료를 통계적 모델로 분석하여 바람지도를 작성하였다. 이 바람지도를 이용하여 지질 통계학 분야의 관측기법인 크리깅 모델을 구성하고, 전역최적화기법인 유전자알고리즘을 이용하여 제약조건을 만족하는 최대에너지밀도값과 그 위치를 도출하였다. 수치최적화 결과 우리나라 풍력 자원의 대략적인 잠재량과 현황파악이 가능하였고, 해상풍력발전단지가 조성 가능한 개략적인 위치를 예측할 수 있었다.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.27-44
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• 2012

The offshore wind farm is increasingly attractive as one of future energy sources all over the world. In addition, the capacity of an offshore wind turbine gets larger and its physical characteristics are big and heavy. In this regard, a special port is necessary to assemble, store, and transport the offshore wind systems, supporting to form the offshore wind farms. Thus, this study aims to provide a policy maker which evaluation factors can significantly affect to the optimal site selection of a offshore wind port. For this, Fuzzy-AHP method is applied to capture the relative weights. The results of this study can be summarized as follows. Five criteria in level I was defined such as the accumulation factor, the regional factor, the economic factor, the location factor, and the consortium factor. Of these, the accumulation factor(37.4%), the location factor(34.2%), and the economic factor( 24.5%) were analyzed by major factors. In level II, three assessment items of each factor were selected so that total fifteen items were formed. To sum up, the site selection of offshore wind port should consider the density of the wind industry, cargo volume of securing the economic operation of terminals, the development degree of offshore wind related industry, and the proximity to the offshore wind farms. In other words, the construction of offshore wind port should be paid attention to considering not only the proximity to offshore wind farms but also the preference of turbine manufacturing companies.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.47-50
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• 2005

본 연구의 목적은 차세대 대체에너지로 각광받는 풍력발전 중에서 육상발전보다 여러 가지 이점이 있는 해상에서의 한국형 풍력터빈 블레이드의 최적 형상을 위 한 알고리즘을 구현하는 것이다. 풍력터빈 블레이드에서 깃익형의 공기 역학적 특성은 매우 중요한 사항이다. 이를 위해서 익형 성능예측에 층류에서 난류로의 천이과정을 포함하는 XFOIL을 이용하여 블레이드 익형 단면의 양력과 항력 분포를 해석하였다. 첫 번째 수준의 설계변수는 운용범위내의 바람의 속도와 블레이드 지름, 축 회전수이며, 각 단면에서의 비틀림각과 시위길이는 두 번째 수준의 설계 변수이다. 운용범위 내의 각 설계점에서 익형의 공력 변수들과 최소에 너지손실 조건을 이용하여 시위길이와 피치각 분포를 최적화하였다. 각각의 설계점에서 결과를 바탕으로 풍력발전의 설계 운용범위에서 반응면을 구성하고 구배최적화 기법을 통해 요구동력의 제약함수를 만족하고 효율을 최대로 하는 블레이드 형상을 구현하였다. 최적형상에 대해 탈설계점 해석을 수행하여 그 성능을 구하였다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.524-530
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• 2020

The risk of offshore wind turbine support structures by scour has been proposed. The proposed utilize probabilities of scour depths and fragilities according to scour depth and a modification of a seismic risk analysis method. The probability distribution of scour depth was calculated using a equation which is suitable to consider marine environmental conditions such as significant wave height, significant period, and current velocity, and dynamic analysis was performed on an offshore wind turbine equipped with an suction bucket to find fragility. Then, the risk of offshore wind turbine support structure considering scour can be found by integrating the scour probability and the fragility.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.222-231
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• 2016

Multi-member lattice-type structures including jackets and tripods are being considered as good alternatives to monopile foundations for relatively deep water of 25-50 m of water depth owing to their technical and economic feasibility. In this study, the reliability analysis of bottom-fixed offshore wind turbines with monopile and/or multi-member lattice-type foundations is carried out and the sensitivities of random variables such as material properties, external wind loadings and scouring depth are compared with respect to different types of foundations. Numerical analysis of the NREL 5 MW wind turbine supported by monopile, tripod and jacket substructures shows that the uncertainties of soil properties affect the reliability index more significantly for the monopile-supported OWTs while the reliability index is not so sensitive to the material properties in the cases of tripod- and jacket-supported OWTs. In conclusion, the reliability analysis can be preliminarily carried out without considering soil-pile-interaction in the cases of tripod- and jacket-supported OWTs while it is very important to use the well-measured soil properties for reliable design of monopile-supported OWTs.